End gate latch



Jan. 15, 1963 P. BLOCK END GATE LATCH Filed March 51, 1960 United States Patent 3,673,637 END GATE LATCH Paul Block, Doonside, Saskatchewan, Canada, assignor of fifty percent to Henry Cote, Wawota, Saskatchewan,

(Ian-aria Filed Mar. 31, 196i), Ser. No. 19,096 1 Claim. (Cl. 292-201) My invention relates to new and useful improvements in end gate latches, particularly end gates installed upon hydraulic dump trucks and the like, wherein the end gate is pivoted by the upper edge thereof and automatically swings open when the dump truck is raised thus permitting the load to be discharged therethrough.

Normally the latch holding the end gate in the closed position is controlled by means of a trip rope extending from the latch to adjacent the operator and this arrangement is most unsatisfactory particularly when there is a relatively heavy load bearing against the end gate.

This method is also dangerous when endeavouring to release the end gate while the truck is in motion, a practice utilized extensively when spreading gravel.

I have overcome the inconvenience and danger attendent to this type of control by providing an end gate latch connected by means of an overcenter linkage to a supporting framework and having a pivoted lever adapted to strike the joint of the linkage thus permitting the tail gate to swing open by means of the pressure thereon. I have found it convenient to operate this lever by means of an electric solenoid connected to the truck battery so that all that is required by the operator in order to release the end gate is to press a button thus energizing the solenoid.

The principal object and essence of my invention is therefore to provide a device of the character herewithin described in which the end gate can be released by the operator readily and easily.

A further object of my invention is to provide a device of the character herewithin described which automatically locks when the end gate swings shut, it being understood that most end gates are situated so that they swing closed when the truck body is lowered.

A yet further object of my invention is to provide a device of the character herewithin described which is locked positively when the end gate is in the closed position irrespective of the pressure against the end gate of the load within the truck body.-

A still another object of my invention is to provide a device of the character herewithin described which is simple in construction, economical in manufacture and otherwise well suited for the purpose for which it is designed.

With the foregoing objects in view, and such other objects and advantages as will become apparent to those skilled in the art to which this invention relates as this specification proceeds, my invention consists essentially in the arrangement and construction of parts all as hereinafter more particularly described, reference being had to the accompanying drawings in which:

FIGURE 1 shows a perspective view of my end gate latch mechanism, sectioned in part, and showing the tail gate of a truck body in the closed and locked position.

FIGURE 2 is a view similar to FIGURE 1 but showing the over center linkage in the broken or released position with the end gate thereby released.

In the drawings like characters of reference indicate corresponding parts in the different figures.

Proceeding, therefore, to describe my invention in detail, reference to the accompanying drawings will show that I have shown in thin line, the rear end 1 of a dump truck body with a tail gate 2 pivoted by the upper edge 3 thereof to the dump truck body in the conventional manner.

Situated beneath the body and supported by means of cross members 3' is a supporting framework 4 consisting of a pair of side plates 5 in spaced and parallel relationship, and a hanger platform 6 and a hanger bracket 7. This supporting framework is situated adjacent the lower rear side 7 of the truck body and adjacent the lower edge 8 of the tail gate when in the closed position.

An angulated latch member 9 is secured centrally adjacent the lower edge 8 of the tail gate by means of bolts 10 and extends forwardly as at 11 to terminate in a down turned hook 12.

A latch keeper 13 is pivoted upon pin 14 within the rear ends 15 of the side members 5 of the supporting framework, said latch keeper including a downwardly extending portion 16, a latch holding ear 17, and a tongue 18, the purpose of which will hereinafter be described. A tension spring 19 extends between the portion 16 of the keeper and the side plates 5 of the supporting framework, normally maintaining the keeper in the position shown in FIGURE 2 when the tail gate is opened.

Over center linkage 20' is pivotally connected by the end 21 thereof to the aforementioned extending portion 16 of the keeper and by the rear end 22 thereof to the hanger platform 6 by means of pivot pin 23. The over center linkage consists of a front link 24 and a rear link 25 pivotally connected together by means of pin 26 and it will be observed that this linkage passes through the hanger bracket 7.

When the tail gate is closed, as shown in FIGURE 1,

the linkage 20 is in a relatively straight line, with the I junction 26 in the locked position, inasmuch as this junction has passed over center. Therefore, the latch 11 cannot be disengaged from the latch keeper 13 irrespective of the pressure applied thereon.

However, as soon as this break joint is broken, pressure of latch 9 on the latch keeper 13 permits the keeper to be rotated to take up the position shown in FIGURE 2 thus releasing the end gate.

The latch keeper and linkage remain in the position shown in FIGURE 2 due to the spring 19 until the tail gate closes by gravity when the dump truck is lowered. At this time the forward surface 27 of the latch strikes the aforementioned tongue 18 and rotates the latch keeper to the position shown in FIGURE 1, locking the linkage and rotating the latch.

I have provided means to break the joint 26' when it is desired to open the tail gate, said means taking the form of a solenoid 28 mounted within the hanger platform 6 and connected by conventional electrical conduit (not illustrated), to the battery of the truck. A switch (also not illustrated) is located adjacent the operators position of the truck which, when closed, completes the circuit to the solenoid and energizes same.

However, it will be appreciated that, if desired, hydraulic or pneumatic means could be provided instead of the electrical solenoid.

A pivoted hammer link 29 is mounted within the hanger platform 6 by means of pivot pin 30, one end 31 of which is adapted to be moved by energization of the sole noid 28.

The opposite end 32 of this link is situated immediately below the joint 26 of the linkage 26 and is so positioned that when the solenoid 28 is energized, the end 32 strikes this joint thus breaking same and permitting the tail gate to open.

Finally, I have provided an adjustment bolt 33 within the hanger bracket 7, said bolt being screwthreadably engaged therewithin. The upper end of this bolt is adapted to contact the underside 34 of the link 24 thus limiting the downward movement thereof.

From the foregoing, it will be appreciated that the 3 position of the joint 26' can be adjusted accurately so that the joint breaks when struck by the end 32 of the link 29 but is over center in the locked position when the tail gate is in the closed position.

Since various modifications 'can be made in my invention as hereinabove described, and many apparently widely different embodiments of same made within the spirit and scope of the claim without departing from such spirit and scope, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

A releasable holding mechanism for end gate latches of dump truck bodies, said mechanism comprising a framework adapted to be secured to the underside of a dump truck body and including a pair of horizontally elongated side members disposed in spaced parallel relation, a U-shaped bracket secured to and depending from said side members intermediate the ends of the latter, a U-shaped hanger depending from said side members at one side of and spaced from said bracket, a transverse fulcrum pin extending between the side members at the other side of and spaced from said bracket, a keeper swingably mounted on said fulcrum pin and adapted to releasably engage an end gate latch for locking the end gate in a closed position, said keeper including an elongated lower portion projecting below the side members of said framework, resilient means connected to said keeper and biasing the same to a latch releasing position, a toggle lever including first and second lever sections having a knuckle joint pivotally connecting the same together, the first lever section extending through said U-shaped bracket and being pivotally connected to the lower portion of said keeper, a transverse pin provided in said U-shaped hanger and having the second lever section pivoted thereon with said knuckle joint of the toggle lever disposed between the U-shaped hanger and the U-shaped bracket, an adjustable screw provided on the bight portion of the U- shaped bracket and engageable by the underside of said first lever section to prevent breaking of said knuckle joint in a downward direction, a solenoid mounted on the bight portion of said U-shaped hanger, a second transverse pin provided, in the U-shaped hanger below the first mentioned transverse pin, an arm swingably mounted intermediate the ends thereof on said second transverse pin below said second lever section, said arm and said second lever section being swingable in a common vertical plane, a pad provided on one end portion of said arm and attractable by said solenoid when the latter is energized whereby to swing the other end of said arm upwardly, and a hammer element provided on said other end of the arm for impacting and breaking said knuckle joint in an upward direction.

References Cited in the file of this patent UNITED STATES PATENTS 709,607 Podlesak Sept. 23, 1902 1,283,669 Chrisman et al Nov. 5, 1918 2,469,113 Hooker May 3, 1949 

